Recognizing Lung Cancer Emergencies

Know when to go to the hospital for urgent medical care

You can experience a medical emergency as a result of lung cancer, regardless of its stage. Issues such as respiratory distress, coughing up blood, confusion, a fever, feeling lightheaded, or sudden weakness signal either an urgent complication of your lung cancer or a side effect of your treatment.

It's important that you learn to recognize signs of an emergency so you can get immediate attention and avoid a decline in your health.

Do You Get a Headache When Coughing?
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Respiratory Distress

Lung cancer may cause respiratory distress, which can be a life-threatening issue.

When you have trouble breathing, you might begin using your accessory muscles to help you breathe; it can feel like your neck muscles tighten as you inhale and/or exhale.

If you experience a sudden change in your breathing, such as increased effort, dyspnea (shortness of breath), a sense of suffocation or panic, or tachypnea (rapid breathing), you need urgent medical attention.

Consider counting the number of breaths you take per minute. An adult who is not physically exerting themselves should take an average of about 12 to 18 breaths per minute; a respiratory rate over 24 is a sign of distress.

Respiratory distress can also cause signs of hypoxia (low oxygen), including:

  • Cyanosis (bluish discoloration of your skin and lips)
  • Dizziness or lightheadedness
  • Confusion
  • A feeling that you might pass out

Your gut feeling is crucial when it comes to respiratory distress. If you're concerned about your breathing—even if you can't describe it—you should get medical help.

Why It Occurs

Lung cancer interferes with your breathing for many reasons. As the cancerous cells multiply, they can grow into healthy lung tissue and induce inflammation. Some lung cancer treatments can cause inflammation as well.

Breathing can be exhausting as you exert yourself while trying to overcome the airway obstruction caused by cancer cells and inflammation.

Other lung cancer complications, including pulmonary embolus (PE, a blood clot in the lungs), or pneumothorax (air leak in the lungs), can lead to a respiratory emergency as well.

Coughing Up Blood

Hemoptysis (coughing up blood) is an urgent medical issue. Coughing up even what looks like a small amount of blood can precede an impending emergency.

This can signal blood loss, which leads to hypotension (low blood pressure) and fainting. And blood that's leaking in the lungs can clot in your bronchi (airways) or alveoli (air sacs), potentially interfering with oxygen and carbon dioxide exchange as you try to breathe.

Usually, hemoptysis is painless, but sometimes severe coughing can also be accompanied by chest soreness.

Why It Occurs

Lung cancer can invade the blood vessels and tissue in the lungs, causing them to bleed—sometimes profusely.

Metastatic lung cancer can spread to areas like the trachea (windpipe) or esophagus (food pipe), which can cause hemoptysis that looks the same as that coming from the lungs—and is equally as dangerous.

Chest Pain

Lung pain and chest pain can be caused by a heart attack, PE, or any heart or lung emergency. These issues can be accompanied by respiratory distress, dizziness, confusion, severe anxiety, and/or loss of consciousness.

Chest pain can manifest in many different ways when you have lung cancer. It may:

  • Feel like tightness in the chest: Some people say it feels like a fist squeezing the chest from inside.
  • Feel like a sharp stabbing or a deep ache
  • Be more noticeable when you breathe deeply or change your body position
  • Be constant and nagging

Often, when it comes to chest pain, there is no time to waste. Immediate medical intervention can be life-saving. Be sure to get medical attention promptly if your chest pain is severe, new, or accompanied by other symptoms. Don't hesitate to call your healthcare provider even if your chest pain feels mild.

Why It Occurs

While lung cancer doesn't necessarily lead to heart disease—a top cause of chest pain—smoking is a risk factor for both diseases.

There are many causes of chest pain associated with lung cancer, including:

Change in Mental Status

A change in mental status can be an emergency for people living with lung cancer. Behavioral changes and an altered level of consciousness can cause a number of different, often vague effects.

Symptoms may include:

  • Confusion
  • Staring into space or being unresponsive
  • Excessive sleeping
  • Stiffening or jerking of the body
  • Agitation or jumpiness
  • Hallucinations
  • Decreased level of consciousness

The problem with a change in mental status is that the person experiencing it is not usually aware of the problem.

If you begin to sense that you aren't feeling like yourself, get urgent medical attention. And if you are with someone and witness a change in behavior or level of alertness, seek professional help for them right away.

Why It Occurs

There are many ways that lung cancer can contribute to altered mental status. Lung cancer can spread to the brain, causing life-threatening compression of healthy brain tissue or brain herniation (the brainstem being pushed out of the skull and down into the spinal cord).

Lung cancer treatment can also increase the risk of sepsis, a severe systemic infection that leads to profound confusion and personality changes. Encephalitis (brain inflammation) due to radiation treatment, chemotherapy, or a brain infection can cause mental status changes as well.

Low oxygen and/or high carbon dioxide levels caused by lung damage can also lead to diminished brain function. And advanced cancer, including lung cancer, increases the risk of stroke.

Fainting or Severe Lightheadedness

Lightheadedness, dizziness, and fainting (often described as syncope) can occur suddenly with lung cancer and may lead to an injury, such as from falling.

Fainting may also be a sign of a number of different lung cancer complications. Some issues that cause fainting may necessitate respiratory support with intubation (placement of a breathing tube).

Signs that you are about to faint include:

  • Sweating
  • Confusion
  • Lightheadedness, dizziness, or trouble catching your balance
  • Nausea
  • Flushing
  • Trembling
  • Feeling like the room is spinning
  • An overall feeling of weakness

Why It Occurs

Lung cancer can contribute to syncope in a number of different ways, and you can experience several of these factors at the same time. Low oxygen, blood loss (due to hemoptysis, for example), and brain metastasis are among the lung cancer complications that can manifest with syncope.

Additionally, heart disease can cause syncope. If you have lung cancer, symptoms like chest pain and syncope will be treated urgently, and then a thorough diagnostic investigation will be done to determine the cause.

And metabolic issues, like low or high calcium, sodium, or potassium, can develop due to metastasis and may affect your level of consciousness.


Swelling in any part of the body can be a sign of edema (fluid buildup), blood flow problems, or a severe allergic reaction. These issues can signal the rapidly worsening effects of your lung cancer.

Lung cancer-associated swelling can manifest with:

  • Puffiness of the arm on one side
  • Swelling and or redness of the face, lips, or eyes
  • Fullness of the head, neck, face and upper chest
  • Wheezing
  • Shortness of breath

Swelling can develop and progress quickly, before you have time to think about what is happening. Get medical help right away, and do not wait to see if it will resolve on its own.

Why It Occurs

Superior vena cava syndrome is a condition in which a vein in the neck becomes obstructed due to pressure from cancer metastasis. The blood can't return to the heart from the head, face, and neck to the heart, resulting in swelling of these areas.

You can also have a reaction to your medication, which can cause anaphylactic shock or angioedema. This can cause swelling, especially of the face, which may be accompanied by wheezing and shortness of breath.

Muscle Weakness/Sensation Issues

Sudden weakness or decreased sensation of the arms, legs, or one side of the body can signal lung cancer metastasis to the spinal cord. Permanent paralysis and incontinence can result if this condition is left untreated, even for just a few hours.

Immediate treatment, usually with a very high dose of steroids, can help reduce the long-term impact of spinal cord compression (SCC).

Other symptoms you can experience include:

  • Back/neck pain or pressure
  • Numbness, tingling, or unusual sensations of the arms and/or legs
  • Loss of bowel or bladder control

Cauda equina syndrome is compression of the spinal nerve roots at the lowest part of the spinal cord. This affects bowel, bladder, and leg function.

Why It Occurs

SCC can occur when lung cancer spreads to the spine (backbone) or spinal cord. A spinal fracture or pressure from metastatic tissue in the spine can impinge on the spinal cord, disrupting its function.

Sometimes, meningeal carcinomatosis can occur when lung cancer metastasis in the brain spreads to the spinal cord (at any or more than one level).


A fever can be a sign of a severe infection, brain metastasis, or it can be a side effect of chemotherapy. When you have lung cancer, the disease or the chemotherapy used to treat it can lower your immune function. This reduces your ability to fight infection and can make infections more dangerous for you.

In addition to fever, you might also have:

When you have a disease like lung cancer, you might experience hypothermia—a low body temperature—instead of a fever. Sometimes your temperature can fluctuate between a high temperature (over 101 degrees F) and a low temperature (below 98 degrees F).

You might need treatment to manage your fever, as well as treatment directed at the specific cause.

Why It Occurs

With lung cancer, your lung disease can predispose you to a lung infection, and decreased immunity can predispose you to an aggressive infection anywhere in the body.

Neutropenia, which is a very low white blood cell count, can occur due to chemotherapy and may lead to high fevers with or without an infection.

Additionally, lung cancer metastasis to the brain can affect temperature regulation if the hypothalamus or the pituitary gland are impacted.

A Word From Verywell

Lung cancer and its treatment can cause a variety of health issues. Even if you experience complications, keep in mind that you can still have a good recovery from your cancer. As you are undergoing treatment, make sure you and the people who live with you are familiar with the complications and the signs of an emergency so you (or they) can reach out for help whenever you need it.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."